The present invention relates to a controller connected via a network and, more particularly, to a method of detecting a connection state between controllers of a multi-chamber system in a semiconductor manufacturing apparatus and a semiconductor manufacturing apparatus performing such a method.
Generally, a semiconductor manufacturing apparatus is provided with various processing chambers that carry out each process to manufacture a semiconductor device in combination. A conveyance mechanism which carries wafers is provided between processing chambers and between a cassette accommodating many wafers and the processing chambers. An apparatus controller is provided to a plurality of processing chambers and conveyance mechanisms so that a desired operation is performed according to the order specification of a semiconductor manufacturing apparatus or the purpose of the user""s use.
The multi-chamber semiconductor manufacturing apparatus including a plurality of processing chambers and conveyance mechanism is provided with a plurality of apparatus controllers or a plurality of CPUs for control. In this case, it is desired to comprehensively control each apparatus controller so as to achieve a complicated work safely, reliably and efficiently. Then, a tightly-coupled type control system of a type, which carries out a bus connection of apparatus controllers to carry out an intensive control, is developed.
However, when the bus connection of each equipment controller is carried out, it is difficult to carry out a maintenance check of the apparatus controllers on an individual basis. Additionally, each apparatus controller and a corresponding processing chamber cannot be operated alone. Furthermore, it is difficult to detach the processing chambers freely.
Accordingly, in order to reduce a system down time, a loosely-coupled type control system has been developed in which apparatus controllers are connected via a network such as the Ethernet so that an individual maintenance and an individual control can be performed. The loosely-coupled type control system is provided with an equipment controller as an upper order controller with respect to the apparatus controller. The equipment controller generally controls the whole semiconductor manufacturing apparatus. In such a loosely-coupled type control system, communication between controllers is performed according to a communication protocol used in the network. Programs, parameter data, control information, etc. for operating the processing chambers and conveyance mechanism are transferred via a network.
When communicating between controllers via a network as mentioned above, it takes a time of an order of several seconds to several tens of seconds is needed (it is dependent on a design) until one controller checks whether a communication connection has been established between the other controller. Additionally, it is impossible fro one controller to distinguish whether the other controller is down or a malfunction occurs in the network when the communication connection cannot be established. Furthermore, an abnormal state of the controller cannot be checked unless it goes through the network. Moreover, it is also difficult to distinguish a case where the controller is not connected from a case where the controller is out of order.
Therefore, when a abnormality occurs in a certain controller or an abnormalities occurs in a network in the conventional control system of the semiconductor manufacturing apparatus in which a plurality of controllers are connected through the network, a time of an order of several seconds to several tens of seconds passes until one controller recognizes an occurrence of an abnormality in a remote controller or a network, that is, until it is determined that the communication connection cannot be established. However, other process chambers or the conveyance mechanism continue to perform regular operations during the time for determining the establishment of the communication connection, when the worst, an unexpected problem may occur in a worst case. Moreover, since it cannot specify whether the generation source of the abnormalities is a network or a controller, a trouble may occur in restoration.
It is a general object of the present invention to provide an improved and useful interlock system in which the above-mentioned problems are eliminated.
A more specific object of the present invention is to provide an interlock system which, when an abnormality occurs in a controller, can discriminate the controller in which the abnormality occurs in a control system of a semiconductor manufacturing apparatus in which a plurality of controllers are connected through a network.
In order to achieve the above-mentioned objects, there is provided according to the present invention a semiconductor manufacturing apparatus, comprising: a processing system containing at least one processing chamber which performs a semiconductor manufacturing process; a conveyance system which takes an object to be processed in and out of said processing chamber; and a control system including at least one apparatus controller, which controls said processing system and said conveyance system, and an equipment controller, which manages said apparatus controller, said apparatus controller and said equipment controller being communicably connected through a network, wherein the apparatus controller and the equipment controller, which are connected via the network, are also connected via a hard wire so as to transmit a status signal inside the apparatus controller and the equipment controller to the control system. Thereby, a presence of each apparatus controller and a status of connection between the controllers can be detected without using communication through the network.
The semiconductor manufacturing apparatus according to one aspect of the present invention is characterized in that said control system further includes a first path, which transmits a status signal of said apparatus controller to said equipment controller via a hard wire, and a second path, which transmits a status signal of said equipment controller to said apparatus controller via a hard wire.
The first path first path preferably includes a path, which transmits a status signal between the apparatus controller and other apparatus controllers. Thereby, since all apparatus controllers can acquire the status signal of other equipment controllers, each apparatus controller can take safety measures in accordance with a status of the control system.
Additionally, it is preferable that the equipment controller comprises means for determining whether or not a communication connection can be established between the apparatus controllers for a further process based on the status signal transmitted from the apparatus controller. Thereby, the equipment controller can avoid waste of time to be generated by trying communication connection between the apparatus controller with which a communication connection cannot be established.
Moreover, it is preferable that the apparatus controller comprises means for determining contents of a further process based on the status signal transmitted from the equipment controller. Thereby, the apparatus controller can electively carry out the safe measures at the time of abnormalities according to the status of the equipment controller or the state of the apparatus controller reflected in the status of the equipment controller.
Additionally, there is provided according to another aspect of the present invention a bootstrap method of a control system of a semiconductor manufacturing apparatus comprising: a processing system containing at least one processing chamber which performs a semiconductor manufacturing process; a conveyance system which takes an object to be processed in and out of said processing chamber; and said control system including a plurality of apparatus controllers, which control said processing system and said conveyance system, and an equipment controller, which manages said apparatus controllers, said apparatus controllers and said equipment controller being communicably connected through a network, characterized by comprising: a step of initializing said equipment controller; a step of detecting a status signal of each of said apparatus controllers connected to said equipment controller via a hard wire; a step of identifying an apparatus controller, which can load a program, from among said apparatus controllers based on the status signals of said apparatus controllers; a step of establishing a communication connection via said network between said equipment controller and said identified apparatus controller; a step of loading a program to be executed to said identified apparatus controller from said equipment controller via said network, and starting the program; a step of detecting the status signal of said identified apparatus controller connected to said equipment controller via a hard wire; and a step of determining whether or not said identified apparatus controller executed said program based on the status signal of said identified apparatus controller.
Thus, by the equipment controller acquiring the status signal of the apparatus controller to which the equipment controller is connected via the hard wire, the bootstrap can be appropriately and efficiently performed in accordance with the configuration of the control system.
Additionally, there is provided according to further aspect of the present invention an interlock method of a control system of a semiconductor manufacturing apparatus comprising: a processing system containing at least one processing chamber which performs a semiconductor manufacturing process; a conveyance system which takes an object to be processed in and out of said processing chamber; and said control system including a plurality of apparatus controllers, which control said processing system and said conveyance system, and an equipment controller, which manages said apparatus controllers, said apparatus controllers and said equipment controller being communicably connected through a network, characterized by comprising: a step of setting a status signal representing an abnormality in one of said apparatus controllers in which the abnormality occurs; a step of transmitting the status signal representing the abnormality of said one of said apparatus controllers to said equipment controller connected to said one of said apparatus controller via a hard wire; a step of transmitting the status signal-representing the abnormality from said equipment controller to all of said apparatus controllers connected to said equipment controller via a hard wire; and a step of performing an interlock operation in each of said apparatus controllers to which the status signal representing the abnormality is transmitted from said equipment controller via the hard wire.
Accordingly, since the apparatus controller can selectively perform the interlock operation when an abnormality is detected in the control system, operators can individually take safety measures in accordance with a condition such as moving to a safe position, waiting after returning a position to resume the operation or waiting at a position where a person can easily access.
Other objects, features and advantages of the present invention will become more apparent from the following detailed description when read in conjunction with the accompanying drawings.